Semitrailer



Sept. 6, 1932. F. L MlLLER 1,875,636

SEMITRAILER Filed Feb. 5, 1931 2 sheets-Sheet 1 F. L. MILLER SEMITRAILER sept. 6, 1932.

Filed Feb. 5, 1951 2 Sheets-Sheet .967 F 1 IE7 Patented Sept. 6, 1932 UNITED s'rxrafsr PATENT OFFICE EEANK Louis MILLER, E PAEEEESBURG, VWEST VIRGINIA,v AssIGNoE. rro mivrs-l MILLER ENGINEERING COMPANY, or EAEKEESBUEG, WEST VIRGINIA, A con- PORATION 0F WEST VIRGINIA j SEMITRAILER This invention relates to semi-trailers, and more particularly to means for operating the front supporting wheels of such devices whereby they may be moved between operative and inoperative positions and supported in such positions. f

An important object of the invention is to provide operating bars connected at one end to the axles or struts of the forward supporting Wheels of a semi-trailer and operative for swinging the struts whereby the vwheels may be moved between operative and inoperative positions.

A further obj ect is to provide novel means for locking the operating bars in either of their two positions. Y

A further object is to provide the operating bars with rack teeth, and to provide novel pinion operated means for the rack bars zo whereby the latter are adapted to move the front supporting wheels of a semi-trailer be` tween operative and inoperative positions.

A further object is to provide a device of the character referred to whichis extremely 2x25 simple in construction and whichzis. adapted to eectively hold the supporting: wheels in operative position when desired.

Other objects and advantages of the inven'- tion will become apparent during the course 3530 of the following description.

In the drawings I have shown oneembodiment of the invention. In this showing,

Figure 1 is a fragmentary plan -view of a portion of the supporting frame of a semitrailer showing the invention applied,-

Figure 2 is a side elevation of thesame, Figure 3 is a front elevationl of the saine, Figure 4 is a section on line 4-4 of Figure 1, and, Y

Figure 5 is an enlarged fragmentary sectional view on line 5-5 of Figure 1.

Referring to Figures 1, 2 and 3, the numeral 10 designates a pair of side rails' forming the supporting frame of a semi-trailer, and the rear end of the trailer is supported by the usual wheels (not shown). vEach side rail is provided near its forward end with a stub shaft 11 secured tothe rail by a nut 12. Each stub shaft pivotally supports a A 5.0 hanger 13 to which are secured the'upper ends of struts 14. The struts are preferably channel-shaped to receive the depending end of the hanger 13, and thelatter is provided with a yseries of openings 15 selectively receiving bolts 16 by means of which the struts may be secured to the hangers in any desired adjusted position with respect thereto. The hangers may be maintained in position on the stub shafts by cotter pins 17.

An axle 18 is arranged across the bottom of the struts 14. Base plates v19 seat against the lower ends of the struts and upon the top of the axle 18, and the base plates are secured to the axle by 'means of U-bolts 20.V The base plates Vcarry upwardly extending portions 21 which are arranged in the channels of the struts and are secured to the struts by bolts 22. Supporting wheels 23 of the usual type are carried by the outer ends of the axleslS and are held in position by nuts 24.

Eachbase plate 19 carries a pair of preferably integral upwardly and rearwardly extending ears 25 and each pair of ears carries a pivot pin 26 securedagainstlongitudinal movement with respect to the ears by Cotter 75 pins 27. Theforward ends of bars 28 are i arranged between the ears 25 and are pivotally connected to the pins 26. Each o-f the bars 28 carries rack teeth 29, as clearly shown in Figures 2, 4 and 5, and one of the bars kis further provided with a pair of openings 30 for a purpose to be described. y

Each side rail 10 carries a depending bracket 31 secured thereto by bolts 32 and arranged a substantial distance rearwardly of 1 the stub shafts 11. Each bracketl rotatably supports a stub shaft 33 having` a polygonal outer end 34. The two stub shafts 33 are connected by a tubular member 35 secured to the stub shafts by pins 36.

A keeper 37 is associated with each bar 2 8. Each keeper includes a top plate 38 seatin against the top of the (associated bar 28, and a. depending side plate 39 surrounding the associated shaft 33. At the other side of each keeper U-bolts 40 extend throug'gh the top plate 38 and around theshaft 33. Within each keeper 37, a pinion 41 is keyed or otherwise secured to the associated shaft 33tobe rotated `thereby,'and the pinions'mesh with .100

the rack teeth 29, as clearly shown in Figure 5.

Means are provided for retaining the rack bars in either ofthe two positions to which they are adapted to be moved upon rotation of the pinions y41. Such means may be associated with both of the rack bars, but only one of the holding means may be employed, as illustrated'in the drawings. Referring to Figure 5 thenumeral 42 designates a'flat resilient plate riveted or otherwise secured at one end to one of the keeper plates 38 as at 43. The opposite end of the plate 42 is offset outwardly of the keeperand extends beyond the lower end thereof to form a handle 44. Inwardly of the handle the plate 42 is provided with a locking finger 45 extending through' an opening 46 in the plate 38, the

l.finger 45 being secured to the plate 42 by upsetting or riveting the upper end of the iinger as at 47. The finger 45 is adapted to be arranged in either of the openings 30 of the Y'associated rack bar 28.

An upwardly extending bolt 48 is secured to the keeper plate 38 with which the locking plate 42 is associated, and the bolt 48 has a nut 49j threaded on its upper end. A coil I spring 50 surrjoundsthe bolt 48 between the nut 49 andthe plate 42 to maintain the lat'- ter in the operative position shown in Figure 5. d

The operation of the device is as follows:

During the operation of the semi-trailer, the wheels 23 and struts 14 normally occupy the dotted line position shown in Figure2, as will be apparent. l/Vhen the parts are in the position referred to, the locking finger 45 is'in engagement with the lower opening 30 whereby it will be apparent that movement of the rack bars will be prevented, and accordingly the wheels 23 will be locked in inoperative position'. n

In this connection, it will be noted that the pinions 41 are fixed against rotation with respect to each other by the connections betweenv the stub shafts 33 and the sleeve 35'. The locking of one rack bar against movement, therefore, also prevents any movement of the other rack bar. It will be apparent, however, that separate locking means for each'rack bar may be provided if desired.

l Vhen it is desired to Vdisconnect'the semitrailer from the truck, the latch handle 44 is moved upwardly to lmove the free end of the plate 42 against the tension of the spring 50 and release the locking finger 45 from engagement with the lower opening 30. The wheels 23 and struts 14 then may be moved downwardly tothe operative position shown in Figure 2, and when theparts reach such vpvosition, the locking finger 45 will snap downwardly into the upper opening 30. The parts thus will be locked in operative positate the pinions and thus move the rack bars upwardly and forwardly until the Vlocking tooth 45 snaps into the lower opening 3() to retain the parts in inoperative position.

It will be apparent that the keepersV 37 are pivoted to swing about the axis Vof the stub shafts 33. Accordingly these keepers are adapted to act as bearings for-the rack bars and they alter theirl positions during movement of the rack bars in accordance with the change in angularity of these elelments as they are moved between operative and inoperative positions.

From the foregoing it will be apparent that the present device is quite simple in construction and may be cheaply manufactured. It also will be apparent that the device may be operated very readily and that the locking means employed is effective for retaining the forward supporting wheels in either of their-two positions. j

It is to be understood that the form of the invention herewith shown andi-described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In a semi-trailer, depending strut means pivotally connected to the body of the trailer to swing betweenoperative and inoperative positions and provided with supporting wheels,`a rack bar pivotally connected at one end to said strut means, a pinion meshing with the teeth of said rack bar at a point spaced from said strut means, and means for locking. said strut means in either of said positions. Y

2. In a semi-trailer, z depending strut means pivotally connected to the body-of the trailer to swing between operative and inoperative positions and provided with supporting wheels, a rack bar pivotally connected at one end to said strut means, a guide for said rack bar, a pinion arranged adjacent said guide and Ameshing with the teethV of i said rack bar at a point spaced from said strut means, and means for locking said strut means in either of' said positions.

3. In a semi-trailer, depending strut means pivotally connected to the body of the trailer to swing between operativerand inoperative positions and provided with supporting wheels, a rack bar pivotally connected at one end to said strut means, a guide keeper for said rack bar pivoted to alter its position in accordance with the angular position of said rack bar, a pinion rotatable about the pivot axis of said keeper and 1neshing with the teeth of said rack bar, and means for locking said strut means in either of said positions.

4. In a semi-trailer, depending strut means pivotally connected to the body of the trailer to swing between operative and inoperative positions and provided with supporting wheels, a rack bar pivotally connected at one end to said strut means, a pinion meshing with the teeth of said rack bar at a point spaced from said strut means, said rack bar being provided with an opening, a pin adapted to be arranged in said opening to lock said rack bar against movement, and resilient means normally urging said pin toward said opening.

5. In a semi-trailer, depending strut means pivotally connected to the body ofthe trailer to swing between operative and inoperative positions and provided with supporting wheels, a rack bar pivotally connected at one end to said strut means, a pinion meshing with the teeth of said rack bar at a point spacedV from said strut means, said rack bar being provided with an opening, a guide for said rack bar maintaining the teeth thereof in engagement with said pinion, said rack bar being provided with a pair of openings, a pin carried by said guide and adapted to be selectively arranged in said openings to retain said rack bar in either of its two positions, and resilient means tending to urge said pin toward operative position.

6. A device constructed in accordance with claim 5 wherein said guide is pivotally supported whereby it is adapted to alter its position in accordance with the angular position of said rack bar.

7. In a semi-trailer, a pair of depending parallel struts pivotally connected at one end to the body of a trailer to swing between operative and inoperative positions, an axle, supporting wheels carried by said aXle, means for securing said axle to the other ends of said struts, a pair of rack bars connected at one end to said securing means, a pinion meshing with the teeth of each rack bar, means connecting said pinions rigidly to each other, and means for locking one of said struts in either of its two positions.

S. In a semi-trailer, a pair of depending parallel struts pivotally connected at one end to the body of a trailer to swing between operative and inoperative positions, an axle, supporting wheels carried by said axle, means for securing said axle to the other ends of said struts, a pair of rack bars connected at one end to said securing means, a pinion meshing with the teeth of each rack bar, means connecting said pinions rigidly to each other, one of said rack bars being provided with a pair of openings, and a lockplate connected at one end to one of saidk guides, said pin being connected to the other end of said plate, and spring means operating against said plate to urge said pin toward voperative position.

In testimony whereof I aiiix my signature.

FRANK LOUIS MILLER. 

